Processing facilities are often managed using process control systems also known as control and instrumentation (C&I) systems. Processing facilities can include manufacturing plants, chemical plants, crude oil refineries, ore processing plants, and paper or pulp manufacturing plants. These industries typically use continuous processes and fluid processing. C&I systems typically manage the use of motors, valves, sensors, gauges and other industrial equipment in the processing facilities. A manufacturing plant or refinery may have several industrial C&I systems such as one or more distributed control systems (DCS), programmable logic controls (PLC), safety system and applications for controlling different processes.
In modern plant engineering, there are C&I systems which include C&I devices that link all plant components (processing units to their respective C&I and between respective C&I systems). The C&I devices include input/output (I/O) modules that generally receive physical parametric (e.g., pressure, temperature) representations from sensors as standard current signals (4 to 20 mA). These signals are utilized by other various C&I devices including for regulating, safety, data acquisition and comparator systems for control, safety and instrumentation purposes. Specifically, conventionally various comparators compare the incoming 4-20 mA signals received from sensors against stored/set “set points” and create outputs used for plant safety, regulation, interlock or/and operation.